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claraty::Bits Class Reference

#include <bits.h>

List of all members.

Public Member Functions
Bits	operator<< (size_t n) const
Bits	operator>> (size_t n) const
Bits	operator~ () const
size_t	size () const
unsigned long	to_ulong () const
std::string	to_str () const
void	print (const char *msg="") const
Assignment/index operations
Bits &	operator= (const Bits &rhs)
reference	operator[] (size_t pos)
bool	operator[] (size_t pos) const
Bit manipulation operators
Bits &	operator &= (const Bits &rhs)
Bits &	operator|= (const Bits &rhs)
Bits &	operator^= (const Bits &rhs)
Bits &	operator<<= (size_t n)
Bits &	operator>>= (size_t n)
Bits &	set ()
Bits &	set_bit (size_t pos, bool val=true)
Bits &	set_bits (size_t pos, size_t n)
Bits &	clr ()
Bits &	clr_bit (size_t pos)
Bits &	clr_bits (size_t pos, size_t n)
Bits &	toggle ()
Bits &	toggle_bit (size_t pos)
Bits &	unchecked_set (unsigned long data)
Bit testing operations
bool	operator== (const Bits &rhs) const
bool	operator!= (const Bits &rhs) const
bool	test (size_t pos) const
bool	is_set (size_t pos) const
bool	get_bit (size_t pos) const
bool	any () const
bool	none () const
Private Member Functions
void	_sanitize ()
Private Attributes
unsigned long	_data
size_t	_Nbits
Friends
class	reference
Classes
class	reference

---

Detailed Description

Definition at line 53 of file bits.h.

---

Constructor & Destructor Documentation

claraty::Bits::Bits	(	unsigned long	val = 0,
		size_t	n_bits = MAX_BITS
	)			[inline]

Definition at line 300 of file bits.h.

References _Nbits, _sanitize(), and claraty::MAX_BITS.

Referenced by operator<<(), operator>>(), and operator~().

   : _data(val), _Nbits(n_bits)
{
  // Constructor
  //
  // default args:
  //   unsigned long val = 0
  //   size_t n_bits = MAX_BITS = sizeof(unsigned long)
  //
  // input args:
  //    unsigned long val --- bit pattern in hexadecimal/octal/decimal number
  //    size_t n_bits --- number of bits ( >= MAX_BITS )
  //
  // Bits b1;                   // b1 = 0000 0000 0000 0000 (_Nbits = MAX_BITS)
  // Bits b1(0x14);             // b1 = 0000 0000 0001 0100 (_Nbits = MAX_BITS)
  // Bits b1 = 0x14;            // same as above (not using assignment operator)
  // Bits b1(0x14, 5);          // b1 = ---- ---- ---1 0100 (_Nbits = 5)
  //
  // Bits(unsigned long) allows automatic type conversion from "unsigned long"
  //   to "Bits" with _Nbits = MAX_BITS
  //
  if ((int) _Nbits > (int) MAX_BITS) {
    // throw out_of_range("Bits::Bits");
    // For now, clamp to MAX_BITS and let user check size to see if it worked.
    _Nbits = MAX_BITS;
    std::cerr << "THROW ERROR: out_of_range - Bits::Bits" << std::endl;
  } else {
      _sanitize();
  }
}

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claraty::Bits::Bits	(	const std::string &	str,
		size_t	n_bits = MAX_BITS
	)			[inline, explicit]

Definition at line 337 of file bits.h.

References _data, claraty::_maskbit(), _Nbits, and claraty::MAX_BITS.

  : _Nbits(n_bits)
{
  // Constructor
  //
  // default args:
  //   size_t n_bits = MAX_BITS = sizeof(unsigned long)
  //
  // input args:
  //    unsigned char* str ---binary-format number, e.g, "0100 0111 0000 1010"
  //    size_t n_bits --- number of bits ( >= MAX_BITS )
  //
  // explicit: no implicit automatic conversion allowed from char* str to Bits;
  //   Bits(const char* str) must be explicitly used for the conversion
  //
  // Bits b1("");               // b1 = 0000 0000 0000 0000 (_Nbits = MAX_BITS)
  // Bits b2("01 0100");        // b1 = 0000 0000 0001 0100 (_Nbits = MAX_BITS)
  // Bits b2("01 0100", 5);     // b1 = ---- ---- ---1 0100 (_Nbits = 5)
  //
  if ((int) _Nbits > (int) MAX_BITS)
    // throw out_of_range("Bits::Bits");
    std::cerr << "THROW ERROR: out_of_range - Bits::Bits" << std::endl;

  _data = 0;    // clear all bits initially

  int i = 0;    // bit index

  // for (int j = strlen(str) - 1; j >= 0; j--) {
  for (int j = str.length() - 1; j >= 0; j--) {

    switch (str[j]) {
    case '0':
      i++;
      break;
    case '1':           // set bit[i] of _data = 1
      _data |= _maskbit(i);
      i++;
      break;
    case ' ':           // skip space
      break;
    default:
      // throw invalid_argument("Bits::Bits");
      std::cerr << "THROW ERROR: invalid_argument - Bits::Bits" << std::endl;
    }

    if (i >= (int) _Nbits) {                    // warning ??????
      std::cerr << "Warning: input data too large" << std::endl;
      break;
    }
  }
}

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claraty::Bits::Bits	(	unsigned long	val = 0,
		size_t	n_bits = MAX_BITS
	)			[inline]

Definition at line 300 of file bits.h.

References _Nbits, _sanitize(), and claraty::MAX_BITS.

Referenced by operator<<(), operator>>(), and operator~().

   : _data(val), _Nbits(n_bits)
{
  // Constructor
  //
  // default args:
  //   unsigned long val = 0
  //   size_t n_bits = MAX_BITS = sizeof(unsigned long)
  //
  // input args:
  //    unsigned long val --- bit pattern in hexadecimal/octal/decimal number
  //    size_t n_bits --- number of bits ( >= MAX_BITS )
  //
  // Bits b1;                   // b1 = 0000 0000 0000 0000 (_Nbits = MAX_BITS)
  // Bits b1(0x14);             // b1 = 0000 0000 0001 0100 (_Nbits = MAX_BITS)
  // Bits b1 = 0x14;            // same as above (not using assignment operator)
  // Bits b1(0x14, 5);          // b1 = ---- ---- ---1 0100 (_Nbits = 5)
  //
  // Bits(unsigned long) allows automatic type conversion from "unsigned long"
  //   to "Bits" with _Nbits = MAX_BITS
  //
  if ((int) _Nbits > (int) MAX_BITS) {
    // throw out_of_range("Bits::Bits");
    // For now, clamp to MAX_BITS and let user check size to see if it worked.
    _Nbits = MAX_BITS;
    std::cerr << "THROW ERROR: out_of_range - Bits::Bits" << std::endl;
  } else {
      _sanitize();
  }
}

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claraty::Bits::Bits	(	const std::string &	str,
		size_t	n_bits = MAX_BITS
	)			[inline, explicit]

Definition at line 337 of file bits.h.

References _data, claraty::_maskbit(), _Nbits, and claraty::MAX_BITS.

  : _Nbits(n_bits)
{
  // Constructor
  //
  // default args:
  //   size_t n_bits = MAX_BITS = sizeof(unsigned long)
  //
  // input args:
  //    unsigned char* str ---binary-format number, e.g, "0100 0111 0000 1010"
  //    size_t n_bits --- number of bits ( >= MAX_BITS )
  //
  // explicit: no implicit automatic conversion allowed from char* str to Bits;
  //   Bits(const char* str) must be explicitly used for the conversion
  //
  // Bits b1("");               // b1 = 0000 0000 0000 0000 (_Nbits = MAX_BITS)
  // Bits b2("01 0100");        // b1 = 0000 0000 0001 0100 (_Nbits = MAX_BITS)
  // Bits b2("01 0100", 5);     // b1 = ---- ---- ---1 0100 (_Nbits = 5)
  //
  if ((int) _Nbits > (int) MAX_BITS)
    // throw out_of_range("Bits::Bits");
    std::cerr << "THROW ERROR: out_of_range - Bits::Bits" << std::endl;

  _data = 0;    // clear all bits initially

  int i = 0;    // bit index

  // for (int j = strlen(str) - 1; j >= 0; j--) {
  for (int j = str.length() - 1; j >= 0; j--) {

    switch (str[j]) {
    case '0':
      i++;
      break;
    case '1':           // set bit[i] of _data = 1
      _data |= _maskbit(i);
      i++;
      break;
    case ' ':           // skip space
      break;
    default:
      // throw invalid_argument("Bits::Bits");
      std::cerr << "THROW ERROR: invalid_argument - Bits::Bits" << std::endl;
    }

    if (i >= (int) _Nbits) {                    // warning ??????
      std::cerr << "Warning: input data too large" << std::endl;
      break;
    }
  }
}

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---

Member Function Documentation

Bits & claraty::Bits::operator=

(

const Bits &

rhs

)

[inline]

Definition at line 416 of file bits.h.

References _data, and _sanitize().

{
  // Assignment operator
  //
  // b2 = b1;           // copies _data, but not _Nbits; zeroes out unused bits
  // b2 = 0x14;         // first does automatic conversion using Bits(0x14)
  //
  // cannot not use the compiler-synthesized default assignment operator that
  //   copies both the _data and _Nbits member data; it is desirable to keep
  //   _Nbits unchanged and zero out the unused high-order bits accordingly;
  //   the idea is similar to the assignment statement that involves
  //   automatic type conversion (e.g., between char and int)
  //
  _data = rhs._data;
  _sanitize();          // zero out the unused high-order bits
  return *this;
}

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Bits::reference claraty::Bits::operator[]

(

size_t

pos

)

[inline]

Definition at line 457 of file bits.h.

References reference.

{
  // single bit element access using b[i] used as lvalue
  // - it sets the member data  _bit_pos = pos first, and then
  //   returns an lvalue temporay object of type "reference" not "reference&"
  // - the returned temporary object together with the assigment operators
  //     Bits::reference& Bits::reference::operator=(const reference&) and
  //     Bits::reference& Bits::reference::operator=(bool)
  //   enables such statement as
  //     b[i] = b[j] = 1;
  //   After the execution, the i-th and j-th bits of b (a Bits object) are
  //   set to 1, and the temporary "reference" object created by b[i]
  //   dissappears.
  //
  return reference(*this, pos);
}

bool claraty::Bits::operator[]

(

size_t

pos

)

const [inline]

Definition at line 475 of file bits.h.

References _data, and claraty::_maskbit().

{
  // single bit element access using b[i]
  // - when returning a built-in type by value, it automatically implies
  //   a "const" return; it returns a value not a variable; namely,
  //   bool f() is the same as const bool f()
  // - the "const" return type cannot be a lvalue
  //
  return (_data & _maskbit(pos)) != 0;
}

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Bits & claraty::Bits::operator &=

(

const Bits &

rhs

)

[inline]

Definition at line 501 of file bits.h.

References _data.

{
  // bitwise AND
  //
  _data &= rhs._data;           // _sanitize unnecessary
  return *this;
}

Bits & claraty::Bits::operator|=

(

const Bits &

rhs

)

[inline]

Definition at line 510 of file bits.h.

References _data, and _sanitize().

{
  // bitwise OR
  //
  _data |= rhs._data;
  _sanitize();
  return *this;
}

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Bits & claraty::Bits::operator^=

(

const Bits &

rhs

)

[inline]

Definition at line 520 of file bits.h.

References _data, and _sanitize().

{
  // bitwise EXCLUSIVE-OR
  //
  _data ^= rhs._data;
  _sanitize();
  return *this;
}

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Bits & claraty::Bits::operator<<=

(

size_t

n

)

[inline]

Definition at line 530 of file bits.h.

References _data, and _sanitize().

{
  // shift left: fill with zeros
  //
  _data <<= n;
  _sanitize();
  return *this;
}

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Bits & claraty::Bits::operator>>=

(

size_t

n

)

[inline]

Definition at line 540 of file bits.h.

References _data, and _sanitize().

{
  // shift right: fill with zeros
  //
  _data >>= n;
  _sanitize();
  return *this;
}

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Bits & claraty::Bits::set

(

)

[inline]

Definition at line 569 of file bits.h.

References _data, and _sanitize().

Referenced by claraty::DIO::_verify_io_mode(), and claraty::DIO_impl::set_IO_direction().

{
  // set every bit to 1
  //
  _data = ~static_cast<unsigned long>(0);
  _sanitize();
  return *this;
}

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Bits & claraty::Bits::set_bit	(	size_t	pos,
		bool	val = true
	)			[inline]

Definition at line 580 of file bits.h.

References _data, claraty::_maskbit(), and _Nbits.

Referenced by claraty::DIO::clr(), claraty::DIO::clr_bit(), claraty::DIO::set(), claraty::DIO::set_bit(), and claraty::DIO_impl::set_IO_direction().

{
  // b[pos] = val; don't change other bits
  // default bool val = true; b[pos] = 1 (set to 1)
  //
  if (pos >= _Nbits)
    // throw out_of_range("Bits::set_bit");
    std::cerr << "Bits WARNING: out_of_range - Bits::set_bit" << std::endl;

  if (val)
    _data |= _maskbit(pos);
  else
    _data &= ~_maskbit(pos);

  return *this;
}

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Bits & claraty::Bits::set_bits	(	size_t	pos,
		size_t	n
	)			[inline]

Definition at line 598 of file bits.h.

References _data, claraty::_maskbits(), and _Nbits.

Referenced by claraty::DIO::clr(), claraty::DIO::DIO(), and claraty::DIO::set().

{
  // extension from STL bitset
  // b[pos] =  ... = b[pos+n-1] = 1; don't change other bits
  //
  if (pos + n > _Nbits)                 // + has precedence over >=
    // throw out_of_range("Bits::set_bits");
    std::cerr << "Bits WARNING: out_of_range - Bits::set_bits" << std::endl;

  _data |= _maskbits(pos, n);

  return *this;
}

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Bits & claraty::Bits::clr

(

)

[inline]

Definition at line 613 of file bits.h.

References _data.

Referenced by claraty::DIO_impl::set_IO_direction().

{
  // set every bit to 0 (clear all bits)
  //
  _data = 0;
  return *this;
}

Bits & claraty::Bits::clr_bit

(

size_t

pos

)

[inline]

Definition at line 622 of file bits.h.

References _data, claraty::_maskbit(), and _Nbits.

{
  // b[pos] = 0 (clear one bit)
  //
  if (pos >= _Nbits)
    // throw out_of_range("Bits::clr_bit");
    std::cerr << "Bits WARNING: out_of_range - Bits::clr_bit" << std::endl;

  _data &= ~_maskbit(pos);

  return *this;
}

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Bits & claraty::Bits::clr_bits	(	size_t	pos,
		size_t	n
	)			[inline]

Definition at line 636 of file bits.h.

References _data, claraty::_maskbits(), and _Nbits.

Referenced by claraty::DIO::clr(), and claraty::DIO::set().

{
  // extension from STL bitset
  // b[pos] =  ... = b[pos+n-1] = 0; don't change other bits
  //
  if (pos + n > _Nbits)         // + has precedence over >=
    // throw out_of_range("Bits::clr_bits");
    std::cerr << "Bits WARNING: out_of_range - Bits::clr_bits" << std::endl;

  _data &= ~_maskbits(pos, n);

  return *this;
}

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Bits & claraty::Bits::toggle

(

)

[inline]

Definition at line 651 of file bits.h.

References _data, and _sanitize().

{
  // change the value of every bit
  //
  _data = ~_data;
  _sanitize();

  return *this;
}

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Bits & claraty::Bits::toggle_bit

(

size_t

pos

)

[inline]

Definition at line 662 of file bits.h.

References _data, claraty::_maskbit(), and _Nbits.

Referenced by claraty::DIO::toggle(), and claraty::DIO::toggle_bit().

{
  // change the value of b[pos]
  //
  if (pos >= _Nbits)
    // throw out_of_range("Bits::toggle_bit");
    std::cerr << "Bits WARNING: out_of_range - Bits::toggle_bit" << std::endl;

  _data ^= _maskbit(pos);
  return *this;
}

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Bits & claraty::Bits::unchecked_set

(

unsigned long

data

)

[inline]

Definition at line 675 of file bits.h.

References _data.

Referenced by claraty::DIO::set(), and claraty::DIO_impl::set_mask().

{
  _data = data;                 // user must ensure data is sanitized
  // _sanitize();               // does not do data sanity check

  return *this;
}

Bits claraty::Bits::operator<<

(

size_t

n

)

const [inline]

Definition at line 784 of file bits.h.

References Bits().

{
  // for return (b1<<3) and also for b2 = b1<<3; b1 unchanged
  // make a left-shifted copy without changing the original object (*this)
  // e.g., the statement b2 = b1 << 3 should not change b1.
  // returns the updated object by value (Bits), not by reference (Bits&)
  //
  return Bits(*this) <<= n;
}

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Bits claraty::Bits::operator>>

(

size_t

n

)

const [inline]

Definition at line 795 of file bits.h.

References Bits().

{
  // for return (b1>>3) and also for b2 = b1>>3; b1 unchanged
  // make right-shifted set
  //
  return Bits(*this) >>= n;
}

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Bits claraty::Bits::operator~

(

)

const [inline]

Definition at line 804 of file bits.h.

References Bits().

{
  // for return (~b1) and also for b2 = ~b1; b1 unchanged
  // make complement set
  //
  return Bits(*this).toggle();
}

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bool claraty::Bits::operator==

(

const Bits &

rhs

)

const [inline]

Definition at line 723 of file bits.h.

References _data.

{
  // for b1==b2 and also for b1==0x14
  // compare _data only not _Nbits
  //
  return _data == rhs._data;
}

bool claraty::Bits::operator!=

(

const Bits &

rhs

)

const [inline]

Definition at line 732 of file bits.h.

References _data.

{
  // for b1!=b2 and also for b1!=0x14
  // compare _data only not _Nbits
  //
  return _data != rhs._data;
}

bool claraty::Bits::test

(

size_t

pos

)

const [inline]

Definition at line 742 of file bits.h.

References _data, claraty::_maskbit(), and _Nbits.

Referenced by get_bit(), is_set(), claraty::DIO::test(), and to_str().

{
  // true if b[pos] is 1
  //
  if (pos >= _Nbits)
    // throw out_of_range("Bits::test");
    std::cerr << "THROW ERROR: out_of_range - Bits::test" << std::endl;

  return (_data & _maskbit(pos)) != 0;
}

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bool claraty::Bits::is_set

(

size_t

pos

)

const [inline]

Definition at line 755 of file bits.h.

References test().

{
    return test(pos);
}

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bool claraty::Bits::get_bit

(

size_t

pos

)

const [inline]

Definition at line 762 of file bits.h.

References test().

{
    return test(pos);
}

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bool claraty::Bits::any

(

)

const [inline]

Definition at line 768 of file bits.h.

References _data.

{
  // true if any bit is 1
  //
  return _data != 0;
}

bool claraty::Bits::none

(

)

const [inline]

Definition at line 776 of file bits.h.

References _data.

{
  // true if no bit is 1
  //
  return _data == 0;
}

size_t claraty::Bits::size

(

)

const [inline]

Definition at line 689 of file bits.h.

References _Nbits.

{
  // get bit size
  //
  return _Nbits;                                // number of bits
}

unsigned long claraty::Bits::to_ulong

(

)

const [inline]

Definition at line 703 of file bits.h.

References _data.

Referenced by claraty::DIO::get_mask(), claraty::DIO::operator unsigned long(), claraty::DIO::output(), claraty::CDIO::output(), claraty::DIO::set(), and claraty::CDIO::set().

{
  // conversion to unsigned long
  //
  // unsigned long x = b1.to_ulong();
  // unsigned short y = b1.to_ulong();
  // unsigned char z = b1.to_ulong();
  // BYTE z = b1.to_ulong();                    // BYTE = unsigned char
  //
  return _data;
}

string claraty::Bits::to_str

(

)

const

Definition at line 34 of file bits.cc.

References _data, _Nbits, and test().

Referenced by claraty::operator<<(), print(), claraty::DIO_impl::to_str(), and claraty::CDIO::to_str().

{
  // Print out the bit pattern of the Bits object
  //
  char buffer[128], *output;
  output = new char[256];               // for contiguous printing on VxWorks

  sprintf(buffer, "[%2d] {", static_cast<unsigned int>(_Nbits));
  strcpy(output, buffer);


  // Convert the Bits to hex ascii
  //
  int n_bytes = (_Nbits + 7)/8;         // number of bytes
  for (int i = n_bytes - 1; i >= 0; --i) {
    sprintf(buffer, "%2x ", static_cast<unsigned int>((_data >> i*8) & 0xff));
    strcat(output, buffer);
  }
  strcat(output, "}  ");

  // Print the bit pattern --00 0110 0010 ...
  //
  int n = (_Nbits + 3) / 4 * 4; // total number of bits in 4-bit period
  int j=0;                      // buffer index for buffer[j];

  for (size_t i = n - 1; i >= 0; i--) {    // i = bit index for b[i]
    if (i >= _Nbits) {
      buffer[j++] = '-';
      continue;
    }

    // if (_unchecked_test(i))
    if (test(i))
      buffer[j++] = '1';
    else
      buffer[j++] = '0';

    if ( (i % 4) == 0  &&  i != 0)      // == and != have precedence over &&
      buffer[j++] = ' ';
  }
  buffer[j] = 0;                // null character ('\0' = 0)

  strcat(output, buffer);

  string s(output);
  delete [] output;

  return s;
}

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void claraty::Bits::print

(

const char *

msg = ""

)

const

Print function.

Parameters:

[in]

msg

Definition at line 90 of file bits.cc.

References to_str().

Referenced by claraty::DIO_impl::print(), claraty::CDIO::print(), and claraty::DIO_sim::set_hw_bits().

{
  cout << msg << "\n  " << to_str().c_str() << endl;    // c_str() will not be
                                                        // needed in the future
}

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void claraty::Bits::_sanitize

(

)

[inline, private]

Definition at line 814 of file bits.h.

References _data, _Nbits, and claraty::MAX_BITS.

Referenced by Bits(), operator<<=(), operator=(), operator>>=(), operator^=(), operator|=(), set(), and toggle().

{
  // zero out the unused high-order bits
  //
  if (_Nbits != MAX_BITS)
    _data &= ~( ~static_cast<unsigned long>(0) << _Nbits );
}

---

Friends And Related Function Documentation

friend class reference [friend]

Definition at line 60 of file bits.h.

Referenced by operator[]().

---

Member Data Documentation

unsigned long claraty::Bits::_data [private]

Definition at line 153 of file bits.h.

Referenced by _sanitize(), any(), Bits(), clr(), clr_bit(), clr_bits(), none(), operator &=(), operator!=(), operator<<=(), operator=(), operator==(), operator>>=(), operator[](), operator^=(), operator|=(), set(), set_bit(), set_bits(), test(), to_str(), to_ulong(), toggle(), toggle_bit(), and unchecked_set().

size_t claraty::Bits::_Nbits [private]

Definition at line 154 of file bits.h.

Referenced by _sanitize(), Bits(), clr_bit(), clr_bits(), set_bit(), set_bits(), size(), test(), to_str(), and toggle_bit().

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The documentation for this class was generated from the following files:

• bits.h
• bits.cc

Last modified: June 05 2007 10:19:53

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